Froth-flotation concentration of ores



Patented Mar. 22;, was

- 'UNiT-E' s'm'ra s WILLIAM TROTTER,'.OF NEW YORK, N. Y., ASSIGNOR TO MINERALS Sl'JPARATION N ORTH AMERICAN CORPORATION, OFNRW YORK, N. :Y A CORPORATION OF MARYLAND IROTE-EIOTATION' CONCENTRATION OF ORES No Drawing.

This invention relates to'the froth-flotation concentration of ores and is herein. illustrated as applied to the concentration of ores whose principal value is carbonate of-copper 6 or carbonate of lead.

Such ores have hitherto proved refractory to treatment for concentration by the agents generally used when following the usual froth-flotation procedures. v

Potassium and sodium xanthate have been extensively used in the froth-flotation concentration of sulphide ores, being usually used in the proportion of a tenth of a. pound or less to a quarter of a pound per ton of ore. Used in such proportions in the froth-flotation process they have markedly improved recoveries and have had other useful results.

But these substances have been without substantial effect when used in these amounts in attempting concentration of carbonate ores by the froth-flotation process. Q

According to the present invention these ordinary agents, as well as agentshitherto 26 commercially untried, may be used according to modified procedures with the result that refractory ores like copper carbonate 1 ores prove amenable to froth-flotation'treatment in the machines hitherto used.

The invention is herein illustrated as car ried out with the organic sulphur-containing compounds known as xanthates, mercaptides, and thio-phenol. It was also found posslble to use para-thio-cresol, thio-beta naphthol, and mercapto-benzo-thiazdle,these being progressively less effective. All the substances thus grouped contain simple sulphhydric radicals such as S H, --S-Na, -S-K,' for example. According to xanthate and other substances are used in much larger amounts than has been cus- *tomary in the froth-flotation process, with 4 the result that a copper carbonate ore 1s as effectively concentrated as is a sulphide ore.

If only the organic sulphur-containing compounds are used in addition to the mineralfrothing agents, at least a pound, usually upwards of two pounds, per ton of ore of such copper andrepresenting51.1% of the the present invention the p Application filed August 4,1926. Serial No. 127.181.

copper, was agitated in a five to one-aqueous pulp with 0.32 pounds of pine oil and 4 pounds of potassium xantha te, both per ton of ore. A brilliant green froth float was obtaining containing 10.44% copper and con taining'94.1% of the copper in the ore. The froth was extremely stable, standing up several hours, dropping some gangue. The concentrates were capable of being easily recleaned.

Em'ample 2:A test similar except that only 2 pounds of the xanthate per t0n.of

ore were used instead of the 4 pounds of Example 1, yielded a smaller float containmg 10.02% copper and representing 79.2%

of the copper in the ore.

Example 3.-Andes. Copper Co. ore containing 1.19% copper largely in the form of copper carbonate, was agitated with a suitable r'nineral-frothing agent and with 4 pounds of potassium xanthate per ton of ore to yield a froth concentrate containing 9.5% copper in the ore.

Example 4.Lead carbonate ore from the Shattuck-Arizonamine in Arizona, containing no identifiable sulphide, was agitatedin a minerals separation subaeration machine for two minutes with 0.32 pounds of pine oil andone pound of potassium xanthate, both er ton of ore, and a first froth concentrate collected. There was then added two pounds moreof the potassium xanthate, agitation continued for two minutes and a second froth a third froth concentrate collected. The

mixed concentrates contained 27.10% of lead and contained 93.0% of the lead in'the ore.

The detailed results are shown in the following table:

Recov- Assays cries Wt. Pb. Pb.

Heads 100. 4. 3 100. 1st Cone 9. 9 30. 66. 4 2nd Cone 2. 6 25. 4 14.8 3rd Cone 2. 8 1S. 3 11. 8 l Tails as 1 0. a7 7. 0

ished concentrate and a middling. The

results are shown in the following table:

Recov- Assays eries pounds of pine oil, per ton of ore, and then a froth concentrate separated for three minutes. There was then further added 4 poupds of thio-phenol, 0.8 pounds of steam distilled pine oil, both per ton of ore, and the pulp agitated for one minute and then a second froth concentrate separated for three minutes. There was then further added 4 pounds of thio-phenol per ton. of ore, the pulp agitated for one minute, and then a third froth separated for three minutes. The results are shown in the following table:

of 1Fpptassium xanthate per ton of ore to yield a Wt. Cu. Cu.%

seas

new

swa

Example 6'.Bwana MKubwa ore ground to pass 65 mesh was made into a pulp with water and agitated for one minute in a subaeration testing machine with 4 pounds of potassium xanthate and 0.48 ounds of cresol, both per ton-of ore, an then a froth concentrate removed for three minutes. There was then added a further 0.32 pounds of cresol per ton of ore, the pulp agitated for one minute, and then a second froth concentrate removed for three minutes. Finally there was further added 2 pounds of the Xanthate and 0.4 pounds of cresol, both per ton of ore, the pulp agitated for one minute, and then a third froth concentrate removed for three minutes. The results are shown in the following table:

Assays Example 7.-Bwana MKubwa ore ground water and agitated for one minute with 0.32

to pass 65 mesh was made into a pulp with T as Recov- Assays erles Wt. Cu. Cu.

Head's. 4. 08 100. 15!. Gone. 6. 71 33. 7 2nd Gone 24. 56 57. 8 3rd Cone 3.61 6. 5 0. 13 2.0

Ewample 8.-In another test 0.30 pounds of cresol and 4 pounds of thiophenol, both per ton of ore, were added together to a pulp of the same ore to form a first froth, instead of the successive addition of pine oil and thiophenol. By this procedure a first concentrate was obtained containing 17.85% copper and representing 85.3% of the copper in the ore.

Example 9.--Bwana MKubwa ore ground to pass 65 meshwas made into a pulp with water and agitated in a subaeration testing machine for one minute with 0.32 pounds of steam distilled pine oil, and then a first froth separated for three minutesf There was further added 4 pounds of potassiumethyl mercaptide per ton of ore, the pul agitated for one minute, and then a second fr ed for three minutes. added 4 pounds of potassium ethyl mercaptide per ton of ore, the pulp agitated for one minute, and then a third froth separated for three minutes. For comparison the same procedure was followed for a fourth and fifth froths, adding potassium xanthate, however, instead of the mercaptide. The results are shown in the following table, from which it will be seen that the mercaptide produced a hitherto unequalled recovery of copper from this ore, although not as good a recovery as in other examples of this specification:

Assays Regsver- Wt.% Cu.% 1

oth separat- There was further stantially dependent 'Para-thio-cresol when dissolved in acetone and then added to an ore pulp in large amounts, yielded, with cresol as a mineralfrothing agent, the same kind of froth as did large amounts of xanthate. When dissolved in caustic soda solution and then added in large amounts to an ore pulp or'copper carbonate ore with pine oil as a mineral-frothing agent, it produced a froth like that characteristic of large amounts of a xanthate,

Thio-beta-naphthol when dissolved in alcohol and then added in large amount to a tone yielded a dirty mineral-bearing froth showing considerable concentration when added in acetone solution to a carbonate of copper ore pulp containing a mineral-frothing a ent and silicate of soda and then agitated. otter results were obtained with a dc slimed ore pulp. It yielded no useful result when added in caustic soda solution under similar conditions.

Having described certain embodiments of the invention, what is claimed is:

1. The process of concentrating ores which consists in agitating a pulp of an ore containing a relatively large fraction of its metal values in carbonate form, under such conditions that a froth bearing such carbonate is.

produced substantially dependent upon the presence'both of an organic mineral-frothing agent and an amount of the order of not less than a pound per ton of ore of an organic sulphhydric compound adapted to float such carbonate, to cause the flotation of such carbonate and of a relatively small proportion of the gangue; and separating the froth. v

2. The process of concentrating ores which values in carbonate form, under such conditions that a froth hearing such carbo'nateis produced substantially dependent uponthe presence both of an organic mineral-frothing agent and an amount of the order of not less than a pound per ton of ore of a'xanthate, to cause the flotation of such carbonate and of a relatively small proportion of the gangue; and separating the froth.

4. The process of concentrating ores which consists in agitating a pulp of'an ore containing a relatively large fraction of its metal values in carbonate form, under such conditions that a froth hearing such carbonate is produced substantially dependent u on the presence both of an organic mineralnothing agent and of about four pounds of an organic sulphhydric compoundadapted to float such carbonate, to cause the flotation of such carbonate and of a relatively small proportion of the gangue; and separating the froth.

' 5. The process of concentrating ores which consists in agitating a pulp of an ore containing a relatively large fraction of copper carbonate, under such conditions that a copper carbonate-bearing froth is produced substantially dependent upon the presence both of an organic mineral-frothing agent and of about four pounds per ton of a xanthate, to cause the flotation of such carbonate and of a relatively small proportion of the gangue; and separating the froth. 1

In testimony whereof, I have aflixed my signature to this specification.

WILLIAM TROTTER.

consists in agitating a pulp of an ore containing a relatively large fraction of copper carbonate, under such conditions that a co per-carbonate-bearing froth is produced su u on the presence both of an organicmineral-Frothing agent and an amount of the order of not less than a pound per ton of ore of an organic sulphhydric compound adapted to float such carbonate,

to cause the flotation of such carbonate and of a relatively small proportion of the gangue; and separating the froth.

3. The process of concentrating ores which consists in agitating a pulp of an ore containing' a relatively large fraction of its metal 

